It's mostly the era Scott... The advancements in CGI since 1997 are HUUUGE. A lot of it is thanks in part to ILM themselves who've had to literally create new techniques as they went along in film making for the prequals... Other companies like Pixar are adding to this too.

The work on the LOTR trilogy made some huge advancements itself. When I saw the way Helm's Deep came together and how it was pretty much a program set up just for that battle, it really put into perspective (for me) the way they advanced things a lot.

In 1997 the effects from CGI were still really "new", and not nearly as fluid and realistic as they are today. At the time they were really cutting edge though. Just as effects in the original trilogy as it originally was were amazing to people at the time.

Hmmm, well with that said methinks this almost looks flawless and fix some pretty bad errors. Hopefully they revisit some of those Landspeeder scenes as well...heck all of the stuff they did in the SE (with the exception of the ANH fight which was great work) should be revisited and brought up to snuff. There are parts of TPM and AOTC that I can't even tell are CGI...compare Jar Jar to Jabba SE and you can really tell how far things went in even 2 years